2004 Sierra 2500HD Low beam headlight problem

[Reedflo22]

Hello all,

This morning while driving my truck I got told at a stop light that my running lights in the back were not working. So when I got to work I got out and checked and sure enough they weren't working so when I left work I turned the truck on and got out to check the lights and they were working just fine. So I though must have been just a connector that wiggled the wrong way. Well 2 days later on the way to work in the morning I realize that my low beam headlights were not working. They have not been working for about 4 days now and I am not sure why. I replaced the bulb, checked the fuses, and even checked the relay and they were all good. All other lights are working just fine including the high beams. I am lost on this and I'm not sure what else to check. Any ideas?

[Chris]

Switch or photocell on the dash might be showing their age

[Cosmic Charlie]

rust - connectors and or grounds ...

[Reedflo22]

Just took the fuse box under the hood out and sprayed all the connections underneath it with contact cleaner and no luck. I have ordered a dimmer switch (the little box on the left that controls the lights) and I am going to try that

[Reedflo22]

Put the switch in today and no luck. I'm just confused on how this happens all of the sudden and its not something simple like a fuse, switch or relay